Motor reversing control



Aug. 7, 1962 w. H. COMERFORD, JR 3,048,757

MOTOR REVERSING CONTROL Filed Feb. 29. 1960 INVENTOR. W\\.\.\AM H.COME.RF'0RD,JR

ATTORNEY United States Patent Ofifice 3,348,757 Patented Aug. 7, 1952 3,048,757 MOTGR REVERSTNG CONTROL William Henry Comer-ford, Ilia, Bellwood, Ill., assignor to Controls Company of America, Schiller Park, 111., a corporation of Delaware Filed Feb. 29, 1%0, Ser. No. 11,661 7 Claims. (Cl. 318-285) This invention relates to a new and improved timer for washing machines or washer-dryer combinations, and particularly to a means for controlling the direction of rotation of these devices.

The present invention is primarily concerned with washers of the type which rotate on a horizontal axis. These devices generally rotate in one direction throughout the washing cycle, which is believed to be the cause of the clothes becoming twisted. It has been found that where the direction of rotation of the washer is periodically reversed during the washing cycle, this tendency of the clothes to become twisted is reduced. Reversal of the washer at the end of each interval has not proven satisfactory because the duration of the intervals available in the basic washer timer is too long.

The primary object of the invention is to provide a means for reversing the direction of rotation of the washer at intervals of a shorter duration than provided in the interval timer.

Another object of the present invention is to provide a means for controlling the direction of rotation of the washer which can be easily integrated into timers now on the market.

Other objects and advantages will be apparent from the specifications and claims as will obvious modifications of the drawings, in which:

FIG. 1 is a side elevation with the housing broken away.

FIG. 2 is taken on line 22 of FIG. 1 showing a side elevation of the drive mechanism.

FIG. 3 is taken on line 33 of KG. 1 showing the switch drive arrangement.

FIG. 4 is taken on line 4-4 showing the arbor drive.

FIG. 5 is a circuit diagram for a single phase capacitor type induction motor.

As seen in the drawing, the timer contemplated herein is of the basic interval type having a pair of terminal boards 1%, 12 which carry program switches generally designated at 14. The terminal boards are carried between end plates 16, 18 and the switches are provided with cam followers (actually the switch blades) which act on cams 2% carried on arbor 22 The arbor is journaled in the end plates for rotation and carries a drive ratchet 24 which is adapted to receive impulses from timer motor as. The drive mechanism for the arbor includes stepping cam 27 secured to disc 28 which is mounted to rotate on motor shaft 30 driven by the timer motor. Lever 32 is pivoted on post 3 4 and biased by spring 36 to force follower 38 into engagement with cam 27. Link 40 is pivoted on the lever and biased by spring 42 so that finger 43 engages the drive ratchet through aperture 45. As the cam rotates, the lever will rock in a counterclockwise direction, advancing the finger to the next tooth on the drive ratchet. When the cam follower reaches the drop portion of cam. 27, the lever will rock in a clockwise direction, advancing the arbor one step. Pawl 44 is pivoted on end plate 18 and biased by spring 46 into engagement with the drive ratchet to prevent reverse rotation when the finger is advanced to the next tooth on the drive ratchet.

The periphery of disc 28 is provided with a cam surface to program switch 48 mounted on plate 50. The switch is provided with a single blade 52 biased into engagement with contact 54 and having a cam follower portion 56 positioned to engage peripheral surface 58 of the disc 28. On rotation of the cam the cam follower on the switch blade will ride up on peripheral surface 60, disengaging the blade from contact 54. The cam follower will then ride up on surface 62, moving the blade into engagement with contact 64. Continued rotation of the cam will reverse the cycle. The peripheral surface of the disc is cut to provide a cycle in which the blade is in engagement with one of the contacts for twenty-four seconds and disengaged from both contacts for six seconds. This cycle may be varied to provide any timed sequence of operation for the switches.

This switch arrangement is applicable only to washer drive motors which can be reversed by actuating a single switch, principally the single phase capacitor type induction motor. As seen in FIG. 5, blade 52 is moveable between contacts 54, 64 with phase displacement for the motor windings 66, 68 provided by capacitor 70. The circuit is connected to program switch 72 so that drive motor reversal will be provided when blade 74 engages contact 76 and unidirectional rotation when blade 74 engages contact 73. Generally, motor reversing is used during the washing cycle only with unidirectional rotation being provided during the spin and drying cycles. The six second delay is provided on cam to allow the motor to slow down before the current is reversed, since a sudden reversal would produce an excessive torque on the drive motor shaft.

This switch arrangement provides a simple means of modifying a basic interval timer to provide periodic control for a specific type drive motor. The transfer of the control of the direction of rotation of the drive motor from the function switches to the reversing switches is synchronized so the drive motor will always be rotating in the same direction when the transfer is made to prevent an overload on the motor. This synchronization is accomplished by molding the stepping cam to the disc so that the intervals for the timer end on the portion of the peripheral cam controlling the required direction of rotation. It will be appreciated that by using a permanently assembled cam a number of peripheral cam surfaces having different time cycles may be provided and that by merely changing the setting of the switch cam follower the user may select different program cycles, i.e., twelve-on, three-off or twenty-four on, six-off. Furthermore, the surface area of the cam may be used to operate sub-interval switches as shown in copending Strathearn application Serial Numher 799,780, filed March 16, 1959. The above combinations indicate the versatility which is possible in a switch of this nature.

Although but one embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

l. The combination with a washing machine having a drive motor and a timer of the type having a cam bank driven by a timing motor through a drive mechanism including an impulse cam molded on a member rotating at a speed greater than timing speed, the impulse cam advancing the cam bank in a step-by-step manner at predetermined intervals to sequence the function switches through a program cycle, said drive motor being connected in circuit with one of said function switches for unidirectional rotation when the switch is closed, of means for periodically reversing the direction of rotation of the drive motor during specific intervals in the timer program comprising, a cam surface provided on the periphery of the rotating member, a single pole double throw switch biased in one direction to a closed position on one of its contacts and moved by the cam to close on its other contact, reversing circuit means connecting the double throw switch to the drive motor to periodically change the direction of rotation of the drive motor, said drive motor function switch being moveable from the drive motor function switch circuit to the reversing circuit means so that the direction of rotation of the drive motor is controlled by the position of the double throw switch.

2. The combination according to claim 1 wherein the cam surface on the periphery of the cam has three levels, one of which holds the double throw switch in a neutral position with the motor circuit open, so the drive motor can slow down.

3. The combination according to claim 2 wherein the impulse cam is integral with the rotating member so that actuation of the drive motor function switch is synchronized with the cam surface on the periphery of the rotating member which controls the direction of rotation of the drive motor corresponding to the direction of rotation provided through the drive motor function switch.

4. The combination according toclaim 3 wherein the drive motor is of the single phase capacitor start induction type motor.

5. The combination with a sequence timer of the type having a plurality of function controlling switches operated by a cam bank driven at timing speed by a motor through a drive mechanism including a stepping cam molded on a member rotating at a speed greater than timing speed, the stepping cam causing sequential operation of the switches at predetermined intervals, of means for providing additional functions during certain intervals comprising, a cam surface provided on the periphery of the rotating member, a single pole double throw switch biased to a closed position on one of its contacts and positioned to engage the periphery of the rotating member, said switch being moved by the cam to close on the other contact, and circuit means including certain of the function switches and the double throw switch, said function switches adding the double throw switch into the circuit during specific intervals to periodically reverse the current to the motor thereby reversing the direction of rotation of the motor during certain intervals.

6. The combination according to claim 4 wherein the cam surface on the periphery of the cam has three levels, one of which holds the double throw switch in a neutral position with the circuit open to provide a timed delay in closing the switches.

7. The combination according to claim 5 wherein the stepping cam is molded on the rotating member so that the impulses delivered to the cam bank is synchronized with the cam surfaces on the periphery of the rotating member.

Kramer Aug. 27, 1929 Shewmon et al. Dec. 7, 1954 

